As someone who had a Wii U also, the amount of games for the Switch I think is not the best. There are genuinely good games, like Super Mario Odyssey, Xenoblade Chronicles 2, and a few others, but there are a ton of re-releases and some of the bigger games like Pokemon Sword I personally found to not be the best or others like Smash Bros aren't really that different from their last release other than having more to do. Can't say anything on Link's Awakening as I skipped because I wasn't interested in the games visuals. That said, Breath of the Wild 2, Metroid Prime 4, that's some good stuff on the horizon.
Speaking of horizon, Horizon 2, Spider-Man: Miles Morales, and a few others will be coming to PS5 within the next year, and of course there's guaranteed to be some big new games to look forward to such as the inevitable God of War 2, whatever Naughty Dog is doing next, the announced Demon Souls Remake.
It's a hard choice. I'd probably look at the exclusives to see what you'd like more and if you would want bigger, more powerful, games, on the PS5, or to have the option to play on the go (Something I barely use). That to me is what separates them more and you can still play your PS4 games on the PS5, which is also nice.